scholarly journals Preparation of SiO2-MnFe2O4 Composites via One-Pot Hydrothermal Synthesis Method and Microwave Absorption Investigation in S-Band

Molecules ◽  
2019 ◽  
Vol 24 (14) ◽  
pp. 2605 ◽  
Author(s):  
Yin ◽  
Zhang ◽  
Wang ◽  
Feng ◽  
Zhao ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Microwave Absorption ◽  
Impedance Matching ◽  
Synthesis Method ◽  
Phase Identification ◽  
Relaxation Processes ◽  
Potential Candidate ◽  
One Pot ◽  
Debye Relaxation ◽  
Attenuation Characteristic

MnFe2O4 NPs are successfully decorated on the surface of SiO2 sheets to form the SiO2-MnFe2O4 composite via one-pot hydrothermal synthesis method. The phase identification, morphology, crystal structure, distribution of elements, and microwave absorbing properties in S-band (1.55~3.4 GHz) of the as-prepared composite were investigated by XRD, SEM, TEM, and Vector Network Analyzer (VNA) respectively. Compared with the pure MnFe2O4 NPs, the as-prepared SiO2-MnFe2O4 composite exhibits enhanced microwave absorption performance in this frequency band due to the strong eddy current loss, better impedance matching, excellent attenuation characteristic, and multiple Debye relaxation processes. The maximum reflection loss of −14.87 dB at 2.25 GHz with a broader −10 dB bandwidth over the frequency range of 1.67~2.9 GHz (1.23 GHz) can be obtained at the thickness of 4 mm. Most importantly, the preparation method used here is relatively simple, hence such composite can be served as a potential candidate for effective microwave absorption in S-band.

Facile synthesis of CuCr2O4 spinel nanoparticles: a recyclable heterogeneous catalyst for the one pot hydroxylation of benzene

2014 ◽  
Vol 4 (12) ◽  
pp. 4232-4241 ◽  
Author(s):  
Shankha S. Acharyya ◽  
Shilpi Ghosh ◽  
Shubhadeep Adak ◽  
Takehiko Sasaki ◽  
Rajaram Bal
Keyword(s):  
Hydrothermal Synthesis ◽  
Synthesis Method ◽  
Facile Synthesis ◽  
One Pot ◽  
Nanoparticle Catalysts ◽  
Hydroxylation Of Benzene ◽  
The One ◽  
Recyclable Heterogeneous Catalyst ◽  
Selective Hydroxylation ◽  
Spinel Nanoparticles

A facile hydrothermal synthesis method is developed to prepare CuCr2O4 spinel nanoparticle catalysts with sizes between 25–50 nm for selective hydroxylation of benzene.

Study on the selective oxidation of methane over highly dispersed molybdenum-incorporated KIT-6 catalysts

2021 ◽  
Author(s):  
Pei Chen ◽  
Zean Xie ◽  
Zhen Zhao ◽  
Jianmei Li ◽  
Bonan Liu ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Mesoporous Silica ◽  
Selective Oxidation ◽  
Synthesis Method ◽  
One Pot ◽  
Oxidation Of Methane ◽  
Highly Dispersed

A series of molybdenum-incorporated mesoporous silica (Mo-KIT-6) catalysts were successfully synthesized by a one-pot hydrothermal synthesis method and were applied in the selective oxidation of methane to formaldehyde using oxygen...

scholarly journals High Efficiency Microwave Absorption Performance of Cobalt Ferrite Microspheres/multi-walled Carbon Nanotube Composites

2021 ◽  
Author(s):  
Hongmei Liu ◽  
Min Zhang ◽  
Kang Hu ◽  
Xiangkai Kong ◽  
Qiang Li ◽  
...  
Keyword(s):  
Microwave Absorption ◽  
High Efficiency ◽  
Magnetic Loss ◽  
Spinel Ferrite ◽  
Impedance Matching ◽  
Relaxation Processes ◽  
Nanotube Composites ◽  
Multi Walled Carbon Nanotubes ◽  
Absorption Performance ◽  
Microwave Absorption Performance

Abstract In this article, spinel ferrite CoFe2O4 and multi-walled carbon nanotubes (MWCNTs) composites are constructed by a facile one-step solvothermal method. The pure phase of CoFe2O4 particles is confirmed by X-ray diffraction patterns. Microstructure analysis demonstrates that monodisperse CoFe2O4 microspheres are wound by MWCNTs. By the introduction of CNTs, there is a significant enhancement in the imaginary part of permittivity (ε″) with the composites. The champion microwave absorption performance can be achieved in the composites by the balance of complex permittivity and permeability. When the mass fraction of CNTs is 3%, a minimum reflection loss (RLmin) of the composites is as high as -46.65 dB at 14.4 GHz at a thin thickness of 1.5 mm, and the corresponding effective absorption bandwidth below − 10 dB reaches 4.91 GHz ranging from 12.41 to 17.32 GHz which covers almost the whole Ku band (12.0–18.0 GHz). In other words, this as-synthesized composites show the most outstanding specific RLmin of -31.1 dB•mm− 1. Such superior microwave absorption behaviors of CoFe2O4/CNTs originate mainly from multiple dielectric relaxation processes, enhanced impedance matching and magnetic loss, as well as the considerable interface between mesoporous CoFe2O4 hollow microspheres and CNTs, and thereby promoting microwave reflection and scattering within the samples. Our results indicate that as-fabricated CoFe2O4/CNTs composites can be a promising microwave absorbent integrating with thin thickness, strong absorption ability, and broad bandwidth absorption.

One-pot synthesis of Ag@silicalite-1 with different silver amine complexes and the performance for styrene oxidation

2021 ◽  
Author(s):  
Hongdan Zhang ◽  
Zhiwei Wang ◽  
Weidu Wang ◽  
Chunyang Wu ◽  
Tingting Lu ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Synthesis Method ◽  
Complex Mixtures ◽  
X Ray Diffraction ◽  
Styrene Oxidation ◽  
One Pot ◽  
X Ray ◽  
Amine Complexes ◽  
One Pot Synthesis ◽  
Amine Complex

A facile one-pot strategy was used to successfully synthesize Ag@silicalite-1 using different silver amine complex mixtures as precursors via a hydrothermal synthesis method. Ag@silicalite-1 was characterized by X-ray diffraction (XRD),...

Preparation and Structure of BiVO4-Graphene Composites

2014 ◽  
Vol 905 ◽  
pp. 101-104 ◽  
Author(s):  
Bin Zhang ◽  
Ya Ling Wang ◽  
Lang Huan Huang ◽  
Shao Zao Tan
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Electron Microscope ◽  
Hydrothermal Synthesis ◽  
Emission Spectroscopy ◽  
Synthesis Method ◽  
Photoelectron Emission ◽  
One Pot ◽  
X Ray ◽  
Transmission Electron

BiVO4-graphene composites were prepared through a one-pot hydrothermal synthesis method, and the structure were investigated by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron emission spectroscopy (XPS), X-ray powder diffraction (XRD) and Transmission electron microscope (TEM). The results show that BiVO4-graphene composites are successfully prepared, and BiVO4 particles are almost uniformly deposited on the surface of graphene.

Synthesis of MnNi–SAPO-34 by a one-pot hydrothermal method and its excellent performance for the selective catalytic reduction of NO by NH3

2017 ◽  
Vol 7 (21) ◽  
pp. 4984-4995 ◽  
Author(s):  
Rui Li ◽  
Zhibin Li ◽  
Liqiang Chen ◽  
Yongli Dong ◽  
Shibo Ma ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Selective Catalytic Reduction ◽  
Hydrothermal Method ◽  
Strong Interaction ◽  
Catalytic Reduction ◽  
Synthesis Method ◽  
Excellent Performance ◽  
One Pot ◽  
Reduction Of No ◽  
Ni Species

MnNi–SAPO-34 with Mn and Ni incorporated in the framework of SAPO-34 prepared by a one-pot hydrothermal synthesis method exhibits excellent NH3-SCR activity, which is attributed to the strong interaction between the Mn and Ni species.

scholarly journals Polypyrrole Chains Decorated on CoS Spheres: A Core-Shell Like Heterostructure for High-Performance Microwave Absorption

Nanomaterials ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 166 ◽  
Author(s):  
Hui Liu ◽  
Guangzhen Cui ◽  
Ling Li ◽  
Zhi Zhang ◽  
Xuliang Lv ◽  
...  
Keyword(s):  
Microwave Absorption ◽  
High Performance ◽  
In Situ Polymerization ◽  
Impedance Matching ◽  
Synthesis Method ◽  
Interfacial Polarization ◽  
Cobalt Sulfide ◽  
Core Shell ◽  
Loss Mechanism

Cobalt sulfide composites have exhibited great potential in terms of microwave absorption, owing to their low price, relatively high capacitance, and excellent electrocatalytic activity. Thus, a novel core-shell like structure comprising cobalt sulfide@polypyrrole (CoS@PPy) composite was synthesized by a facile solvothermal synthesis method and in situ polymerization. When coated by the heterostructure polypyrrole aerogel, CoS@PPy composite exhibited excellent microwave absorption properties with an optimal reflection loss (RL) of −41.8 dB at 6.96 GHz. Furthermore, the absorption bandwidth (RL < −10 dB) of 5.4 GHz could be reached at a coating thickness of 2.05 mm, probably attributing to the synergistic effect of good impedance matching, interfacial polarization, dipole polarization, and conductivity loss. Moreover, this work proposed a loss mechanism mode which probably occurred in the CoS@PPy composites. It was demonstrated that the CoS@PPy composite is a promising material in the field of electromagnetic wave absorption.

Green and facile synthesis of highly biocompatible carbon nanospheres and their pH-responsive delivery of doxorubicin to cancer cells

RSC Advances ◽  
2015 ◽  
Vol 5 (23) ◽  
pp. 17532-17540 ◽  
Author(s):  
Xiaoli Liu ◽  
Hui Jiang ◽  
Wei Ge ◽  
Changyu Wu ◽  
Donghua Chen ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Cancer Cells ◽  
Bacterial Cellulose ◽  
Cellulose Nanofibers ◽  
Synthesis Method ◽  
Ph Responsive ◽  
Carbon Nanospheres ◽  
Facile Synthesis ◽  
One Pot

Carbon nanospheres with size below 71 nm are synthesized from bacterial cellulose nanofibers using a one-pot hydrothermal synthesis method.

One-pot hydrothermal synthesis of RGO/CoFe 2 O 4 composite and its excellent microwave absorption properties

2014 ◽  
Vol 114 ◽  
pp. 52-55 ◽  
Author(s):  
Meng Zong ◽  
Ying Huang ◽  
Haiwei Wu ◽  
Yang Zhao ◽  
Qiufen Wang ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Microwave Absorption ◽  
Absorption Properties ◽  
One Pot ◽  
Microwave Absorption Properties

Synthesis and Characterization of Pt-Sn Incorporated MCM-41 and Pt Incorporated Sn-SiO2 Type Mesoporous Catalysts for Direct Ethanol Fuel Cell

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
Dilek Varisli ◽  
Tugba Rona ◽  
Niyazi Alper Tapan
Keyword(s):  
Hydrothermal Synthesis ◽  
Oxidation Behavior ◽  
Synthesis Method ◽  
Molar Ratio ◽  
Alloy Formation ◽  
Direct Ethanol Fuel Cell ◽  
One Pot ◽  
Platinum Particles ◽  
Electro Oxidation ◽  
Mcm 41

In this study, Pt-Sn incorporated mesoporous silicate materials were synthesized and characterized, and their activities in ethanol electro-oxidation reaction were tested by cyclic voltammetry. Two groups of catalysts were prepared. In the first group, Pt@MCM-41 and Pt-Sn@MCM-41 were prepared by impregnation of Pt and Sn onto MCM-41 support, which was synthesized by one-pot hydrothermal synthesis method. We adjusted the Pt/Sn molar ratio of 2 in the synthesis solution, and the Pt-Sn alloy formation was recognized beside large platinum particles for Pt-Sn@MCM-41. In the second group of catalysts, Sn-SiO2 was prepared by one-pot hydrothermal synthesis procedure with a Sn/Si molar ratio of 0.014 and was used as support material for Pt. Tin oxide phase was well dispersed through silicate structure and only large Pt particles were found in the XRD analysis of Pt@Sn-SiO2, in which the Pt/Sn ratio was 2. In order to see the effect of Pt/Sn molar ratio on the structural and catalytic activity of the catalyst, Pt@Sn-SiO2(3:2) was prepared by changing the Pt/Sn ratio to 3/2 and obtaining smaller particles for the later one. After electrochemical activity tests in 0.5M H2SO4 and 0.5M H2SO4 + 0.5M C2H5OH electrolyte environments, it was seen that Pt@MCM-41, Pt-Sn@MCM-41, Pt-@Sn-SiO2(3:2) and Pt@Sn-SiO2, exhibit different ethanol electro-oxidation behavior, which is assumed to be due to different pore and crystalline size. Sn-SiO2 supported Pt showed the highest oxidation currents after 0.6V vs. RHE. An ethanol oxidation behavior of Pt@Sn-SiO2(3:2) and polycrystalline Pt was very close at 0.6V vs. RHE.

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